To investigate the impact of the commonly used pyriminobac-methyl (PM) residue in rice fields on P. canaliculata, we exposed it to sublethal concentration of 1.9 mg/L and 0.019 mg/L. Growth measurements and transcriptomic analysis showed a biphasic impact at these concentrations. Toxicity tests showed that the Lethal Concentration 10 % of pyriminobac-methyl for small P. canaliculata was 19.27 mg/L at 72 h. At 0.019 mg/L, it boosted the size and weight of P. canaliculata and increased digestive enzyme activity, while 1.9 mg/L inhibited growth and reduced enzyme activity. Histopathological analysis indicated foot and liver damge affecting feeding. Transcriptomic analysis identified BXL2 and CelA as key genes in energy metabolism, with 0.019 mg/L lower enhancing and 1.9 mg/L reducing their expression, impacting growth and their role in regulating enzyme activities and growth was confirmed by RNA interference. The underlying mechanism may involve the synergistic expression of the BXL2 and CelA genes in response to the PM, leading to a biphasic effect. These dual responses likely contribute to the uncontrolled spread of the species. Understanding the mechanisms behind these biphasic effects provides valuable insights for controlling P. canaliculata spread globally and mitigating its ecological consequences.
Lu et al. (Thu,) studied this question.